Earth borehole investigation-signaling system



Man

Aug. 14, 1956 EARTH BOREHOLE INVESTIGATION-SIGNALING SYSTEM Filed July 14, 1954 J. J. ARPS 2 Sheets-Sheet 1 c/fiA/d. FEDS,

INVENTOR.

' ,QGEA/ g- 14, 1956 J. J. ARPS 2,759,143 EARTH BOREHOLE INVESTIGATION-SIGNALING SYSTEM Filed July 14, 1954 2 Sheets-Sheet 2 u u, pens, 5 6 5: INVENTOR.

Unite States Patent 0 EARTH BOREHOLE INVESTIGATION -SIGNALING SYSTEM Jan J. Arps, Dallas, Tex. Application July 14, 1954, Serial No. 443,308 14 Claims. (Cl. 324-1) This invention relates to a system for communicating 15 or signaling information from a relatively inaccessible location in an earth borehole to a location outside the borehole at the earths surface. More particularly, the invention relates to such a system adapted for operation during drilling of the borehole as well as during periods 20 of suspension of the drilling. Still more specifically, the present invention relates to such a system wherein there are no electrical connections between the inaccessible location in the borehole and the location exterior of the borehole, all of the electrical apparatus being located at either of said locations.

Previously proposed systems of earth borehole investigation or logging and capable of operation during drilling of the borehole have utilized a pressurized downwardly flowing stream of drilling fluid within the drill string as a communication medium for the transmission of intelligence from an inaccessible location within the borehole to the surface of the earth; see, for example, applications Serial Nos. 346,457 and 295,982, filed April 2, 1953, and June 27, 1952, respectively. In such previously known systems signals were created in the drilling fluid stream in the vicinity of the lower end of the drill string by valve means which when operated electromagnetically or otherwise, produced an increase in pressure in the fluid of the stream which signal was quickly transmitted to the exterior of the borehole and translated and recorded by transducer and recording means of suitable design. Further, such systems utilized various arrangements of time spaced pressure changes to represent information concerning items of interest investigated in the vicinity of the bottom of the borehole. With such systems of time-spaced pressure increases confusion of intelligence is apt to occur unless the system is restricted to but one type of intelligence, or unless excessively long periods of time are allocated to each type of information or intelligence. The 50 present invention provides a system wherein such disadvantages and defects of the previously known systems are obviated, and has as a principal object the provision of a system of the type mentioned in which two types of intelligence or information may be concurrently transmitted or signaled on the common single communication medium of the drilling fluid, without any likelihood of the two types of intelligence becoming confused or mixed.

It is another object of the invention to provide a simple and efficacious system for rapidly and surely transmitting two different types of intelligence or information from a relatively inaccessible point within an earth borehole to a location outside the borehole.

Other objects and advantages of the present invention Will hereinafter be made apparent in connection with a description of a preferred embodiment of apparatus ac- 5 cording to the system of the invention.

While a wide variety of types of intelligence or information concerning items of interest to be investigated in the vicinity of the bottom of the borehole may be handled with equal facility by the system of the present invention, 0

for purposes of illustration two items of interest commonly forming the subject of investigation of ordinary electrical logging systems; namely, earth current path resistance and natural potential of the earth, are arbitrarily selected to illustrate operation of the invention.

Generally, the system of the present invention utilizes as a signal transmission medium the downwardly flowing pressurized stream of drilling fluid within the hollow interior of the drill string, but differs from the previously proposed systems in utilizing two different types of pressure changes within the drilling fluid stream to form signals representing two diiferent channels of information. The pressure changes comprised in the signals according to the system of the present invention are, as stated, of two types, the first type being in the nature of a pressure increase, and hereinafter referred to as positive, and the second type being in the nature of a pressure decrease and hereinafter referred to as negative, both such changes in pressure being measured from an average or normal prevailing pressure in the drilling fluid stream. The pressure change producing device may assume a wide variety of forms within the spirit of the invention, but as hereinafter illustrated and described by way of example, comprises an electromagnetically operated drilling fluid valve arranged to assume three different operating positions. In the normal position of this valve, which is assumed when neither of its two operating electromagnets is energized, the valve offers a certain amount of resistance to flow of the drilling fluid therethrough or therepast, thereby producing a detectable pres-sure differential between a point in the drilling fluid stream above the valve, and a point in the drilling fluid stream below the valve. A positive or pressure rise producing position is assumed as a result of energization of a first of the valve electromagnets, and results in an increased resistance to flow of drilling fluid therethrough or therepast; and a negative or extreme open position is assumed as a result of energization of a second of the actuating electromagnets, in which latter position the valve offers substantially no, or very little, resistance to flow of drilling fluid therethrough or therepast. The means for investigating various items of interest within the borehole and for formulating signals indicative of such information may, within the spirit of the invention, assume a wide variety of forms. It is only necessary that such means be capable of reducing each type of information or intelligence to respective time-spaced electrical current pulses in individual circuits, the time intervals between the pulses being indicative of, or representing, the information or intelligence. In the preferred embodiments of a system according to the invention as hereinafter illustrated and described, a time clock controlled structure including a periodically acting set of cam actuated contacts and power supply means is arranged to energize one of the valve actuating electromagnets in such a manner that the valve produces a series of regularly time-spaced reference pressure-change signal elements in the drilling fluid stream. Also included are two information registering or measuring devices cyclically operated by the time-clock means of said structure and each effective to energize a respective one of the actuating electromagnets of the valve to produce a pressure change signal element in the drilling fluid stream. The polarities, or conditions of the two pressure change signal elements produced by the action of the two devices will be opposite, that is, one positive and the other negative. The two pressure-change signal elements produced by action of the mentioned devices are each spaced in time following the reference pressure change signal element, the individual time-spacing being a measure of, or otherwise representative of, the particular information or intelligence being conveyed by the respective positive or negative element of the signal. The time-spacing of the reference signal eleinents of a series of signals is automatically efle'ctedby.

time spacing of the information representing positive and meaushereinafter more specifically: disclosed, so that the time interval between a reference signal element and a next following positive signal elementrepresents one measurement-or registration of one type of information and so that the time interval between the reference signal elementand the next following negative signal element similarly represents the other information.

A preferred embodiment of apparatus operable to perform the method of the invention and otherwise conform-i ing to the system of the invention is illustrated n the accompanying drawingsin which; Figure l is a diagrammatic illustration, partly in vertica'l section, of a typical earth borehole and earth borehole drilling rig with a system according to the present I invention applied thereto;

I Figure 2 is a. view, partly in longitudinal section and to an exaggerated scale, of a portion of the structure shown at the lower end or Figure 1.;

ducing position; I I p I p a Figure 5 is a schematic andelectrical circuit diagram of apparatus contained in a; drill collarof the drill string 'adjacent't-he lower part of Figure-l; and i Figure .6 is a graphical representation ofa recordprovidedby signal receiving and translating apparatus located exteriorl'yof the borehole at the surface of the earth.

Referring now to the drawings, and to Figure 1 in particular, there is depicted in section andin somewhat simplified forrn a typical earth borehole which may penehate the earth in any desired direction, but which is shown extending generally downwardly, and being drilled by drilling means which-comprises a sectional string of drill pipe 11 connected at its lower end to a sectional drill collar 12 to the lower end of which is in turn secured a rotary drill bit 13 which upon rotation produces an extension of the borehole 10. The upper end of the string of drill pipe '11 is suspended from at Kelly bar .14 which is in turn suspendedfrom a rotary swivel 15. The rotary swivel s supported for vertical movement by conventional means including a traveling block and a crown block and wire rope operated by a drawworks as is usual and well known 1n the art. As the drill string comprising Kelly bar 1-4, drill pipe 11, drill collar 12 and drill bit 13 is slowly lowered as drilling proceeds, the earth borings or chips removed by bit 13 are carried .to the surface in a stream of .drilling Jfluid or mud which flows in the free space within the borehole surrounding the outside of the drill string; the drilling 'fluid and chips being discharged from an upper cased portion of the borehole through a side discharge pipe 16 into a settling pit or other conventional fluid recovering means 17. From a suitable portion of the means 17 the relatively free or cleaned drilling fluid is withdrawn through an intake pipe 18 into a drilling fluid pump 19 from which it is discharged under considerable pressune past a surge tank 20 into a conduit 21. The stream of drilling fluid supplied to conduit 21 is delivered through a rotary hose 22 to the aforementioned rotary swivel .15 through which it is delivered in turn to theinte nor of hollow Kelly bar 14 from which it flows downwandly through the interior of the drill string to orifices in the drill bit '13. The purpose of surge tank 20, which may beconventional, is to dampen or remove to the greatest possible extent pressure fluctuations in the drilling fluid stream :caused by action of pump 19 and other actions incident to the drilling. The thus far enumerated structure, with the exception of drill collar 12, is or may be such as is used in conventional drilling practice and is.

the cam actuated contacts as hereinabove noted, and the.

' negative'si'gn'al elements is also automatically adjusted, by

depicted and thus briefly described to portray an environmerit of the present invention.

Referringnowto Figure 12, drillcollar 12 is shown as comprising anupper section 23, an: upper sub 24,.a special section 25 whose construction will hereinafter be more fully explained, and a lower section 26' to which drill bit 13 .is secured. T he downwardly flowing stream of drilling fluid is delivered by upper section 23 of the drillcollar to the specially shaped internal. bore 27 of sub 24, in

which bore the aforementioned pressure changes in the I V drilling fluid stream are adapted to ,be effected. Bore 2'7 at its upper portion is of substantially uniform diameter, but diverges at itslower portion in a sectionof increasing diameter, reaching a maximum diameter in the region where the interior "bore of special section 25 joins the bore of -sub24. Special drillcollar scction25' is, as depicted,

- of relativelylarge internal diameter, whereby there may the interior wall of section 25. in legs are circumferentially spaced apart around the be positioned and supported in the drilling fluid stream agenerally cylindrical apparatus case 28 provided with upper and lower sets ofrsupportinglegs 30 and 31, respectively, which legs are suitably 'f ormed-tosnugly engage exterior peripheryof' the apparatus case and are preference. Further, two or more or such legs-may be of 'special cross-sectional shape as hereinafter more fully explained, whereby electric conductors may be led from a the interior of case 28 and throughsuitable apertures in ably of smooth streamlined form, whereby the streamof' may flow therepast without. undue interfere drilling fluid formed special drill collar section 25. The drilling fluidistream passing downwardly aroundthe exterior periphery of apparatus case 28 flows in the} d'irectionindicated generally I bythe streamlined arrow'pointed lines, into'the'bore of I lower sub 26, from which it is delivered to the drill bit 13. Apparatus case 23 isemployed'to house means for investigating items of interest adjacent the lower end of the p drill string, a power supply means, valve means, and sub-' sidi-ary'equipment "whose function is, with other means which may be conventional, to actuate a three-position valve means at proper times and in the proper manner to produce the aforementioned pressure change signal elements.

The valve means utilized to produce the pressure changes in the drilling fluid stream may assume any of a variety of physical forms. That chosen to illustrate the preferred embodiment of apparatus according to the invention, comprises a lower shaped portion of the wall of bore 27 of the sub '24 and a complementarily formed shaped valve head 35 fixedly mounted on the upper end of a valve rod '36 mounted as indicated for vertical reciprocation in the upper and cap piece 28a of apparatus case 28. Valve rod 36 is of three-piece construction and comprises an upper section 36a and a lower section 36c, both of nonmagnetic material and both rigidly secured to a central section 36b of ferromagnetic material. Upper section 36a is adapted to be guided by suitable bearing and packing means formed in the upper cap piece 28:: of case'28; while lower section 36c is arranged to be guided in conventional bearing means provided in a suitable valve rod guide disc 37 secured in the interior of case 28 as indicated. The lower end of rod section 36c is surrounded by a compression spring 38 abutting against disc 37 and pressing against a disc 39 suitably affixed to section 360, spring 38 serving to hold the valve rod 36 and valve head 35 in approximately the position illustrated in Figure 2 with a normal stream of drilling fluid flowing, and with neither of the hereinafter described valve electromagnets energized. Secured in the upper interior of the casing 28 and encircling valve rod .36 are two valve actuating electromagnets 40 and 41, each comprising a ferromagnetic outer case and a coil .or winding Within the case; the two magnets sharing The' respective supporte aeqp edspae iht e li -f q lqffimj rlfi' Pts esahh' ll ts wit a sui ble sem ihg u d shah a P l 9J1 tP flWiQ5 such as bellows means 42 c9; I. A f h the ilb rin flu d st e a d eea e in h ,i e e re ea e 28 h R t de t show e ee eest the emea .Q IIQd 36 int r ude-h efrthe ea e he a er ess ih d a rang m n e valve st s h is s eh tha with neithe relee mesh 4 a 41 ner is d s i g 548 sad the drilling [fluid stream act to vposition valve hea Q6 t e id vme hm e f estti tiehs herlh l n fluid stream.therepast, and suchttllat when the upper elec- I emasne thi ene gi d; va r ds et en 39 s d h wefd ys e ih, e e e 3 unw dl t he y sh et w o d in flu de t leehs eP e nie me iees in th d l i 'fih d st eam he e 'v and i rthcrsuch that uponenergization of electromagnet .41, w ye red t eetie .3 i s -e s do n a d t deavalve head ,35 ,down against or closely adjacent the vhll e tfaee tqf endear 2 a f easing ls th ereby suhstantrally removing all restriction ofier'ed by the valve head 5 t the marina d i n flu d stree h-v Thehq me s n t a vposit of val he d is ide ie e t h .E ehte the l p pes h :Wh ih e Pres h e ere i iaslh ei indicated in Figtl re 3 and ,the lower position'in w h a ,neea i 'pres 'e eh a re a e nthe d llih .flhts 2"- 'streagn is indicated in Figure 4.

, IQm h afe e se ed epe t eh f the valve .meah ih e ipe ed i h drilling d st am i is tha a stess e ehe ee ithe p s tive 9 ne a e ehst eter .IREEY h p eslhe s th str am bove th va v hyse ea ;hole logging operations employed obtaining rnfortna- 'tion concerning earth path resistances and ,the natural potential of earth formations adjacent theborehole. 'Ih e 'nature and arrangement of the insulatingjjacket and the electrode system are not per s e of the present-invention,

may be of conventional arrangement' and construction,

and are depicted solely as one form of suitable plea us of obtaining information concerning items 10f interest within 'the borehole for transmission from within the bore hole-to thesurfa ce ofthe earthby a system according'to the present invention.

Referring now to Figure 5 of the drawings, a schematic circuit diagram is shown of apparatus comprised in a capsule '55 contained within apparatus case 28 in the interior of the drill collar. The circuit diagram also'indi- Oates diagrammatically the aforementioned electrodes 50, 51, 52 and 53. The electromagnets 40 and 41 areind icated in position to selectively operate the aforedescribed valve, here identified by the reference character V. Electroma-gnet 40 is indicated as having its coil connected in series with a suitable source of electric power such as a battery 60 and to parallel-connected circuit-closing sets-of contacts including a set 61 regularly and periodically closed-by-camtmeans, and a second set*6 2 operable by a relay R1, closures of these sets of contacts being effected at times as hereinafter more fully described. 165

aElectromagnet .41 is connected in series ivith a suitable source of electric power such as battery 65 and a set abnormallyopen contacts 66 forming part of a rcIay RZ, whose coil when energized is adapted to close said con- .tacts tagainsttthe :forcelexertedtbya relay-spring. Con- 7 0 tests J61 are .adaptedto-be periodicallyclosed by atregu- .1 1

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marks or other indications occurring at regularly spaced intervals. The spacing of the information-representing pips or marks vary as the values they represent vary.

Referring again to Figure l, the pressure change signals in the drilling fluid stream created by valve V and representing items of interest such as physical quantities or measures thereof, are quickly transmitted upwardly through the fluid in the hollow drill string and are impressed upon a receiver-recorder means'indicated generally by reference numeral 90, which serves to receive and translate the pressure change signals into sense-perceptible indications of the two types of information secured by the investigating apparatus at'the bottom of the drill string. This signal receiving translating and recording apparatus may be supplied with electrical energy from a generator in the draw works through leads 91 and 92, and may be of conventional form comprising a conventional pressure transducer whose output is preferably amplified and fed into a conventional electrical recorder mechanism. In regard to the recorder apparatus, it is essential only thatit be operated at a uniform rate of speed as, for example, by a time clock mechanism, to produce a graphical or other sense perceptible indication of the pressure variations in the drilling fluid stream in conduit 21.

Referring now to Figure 6, there is indicated diagrammatically a length of a typical graphical recording produced by the means 90 operating according to the system of the invention. The graphical recording is a record of the drilling fluid pressure, P, in conduit 21, plotted against time, t. The recording includes two reference pressure change signal element marks or pips PCR, spaced apart a distance representing a time period T. Also the recording includes positive and negative pressure change signal element marks PC1 and PCZ, spaced from the preceding reference mark PCR by respective distances representing time periods T1 and T2, respectively. The latter time periods, and the corresponding distances on the record, are directly proportional to the values measured in the borehole and represented by the pressure change signal elements. Thus the method of evaluating the record is obvious. The only possibility of confusion arising from operation of the system according to the invention resides in the impossibility of producing both a positive and a negative pressure change signal at the same time. This possibility of confusion is readily avoided by proper selection of the values of the circuit elements of the bridge network and of the potentiometer network so that the signal resulting from one of said networks with invariably precede, or invariably follow, that produced by the other of the networks. Further, it will be evident that even if the full range of time between reference pressure changes were to be utilized for each of the types of information or information channels, only in rare instances would any values of the information be encountered which would result in attempted formation of concurrent positive and negative pressure changes. In such rare instance, fluctuation or variation of one or both of the measured values would cause noncoincident signals to be transmitted before and after any attempted coincident signals, whereby by interpolation and/ or extrapolation the values represented by the coincident signals could readily be ascertained.

Thus, it is seen that the system of the invention provides a means and method of concurrently transmitting information of two distinct types from a location within an earth borehole to a location outside the borehole, without electric connections between the two locations and without danger of mixing or confusing the types of information; and that the other stated and obvious objects of the invention are fully accomplished. While a single preferred embodiment of apparatus according to the system of the invention has been illustrated and described, it is evident to those skilled in the art that the apparatus may assume a wide variety of forms within the spirit and seope of the invention; and it accordingly isinot desired to-limit the invention to the specific details disclosed, but what is claimed is:

1: In a system for communicating information of two types from a relatively inaccessiblelocation in an earth borehole/to a point outside the borehole while concurrently extending the borehole by drilling with means in cluding a hollow drill string through which a stream of drilling fluid flows under pressure, apparatus comprising: a section of such drill string; means in the section of drill string to recurrently measure each of two physical quantities and to produce in such stream pressure change signals, each comprising one of a series of regularly produced reference pressure change signal elements of a given character and two information-representingpressure change signal elements one above and the other below an average pressure value and each representing a respective measure of said physical quantities; and means outside the borehole for receiving and translating said signals.

2. In a systemfor communicating information of two types from a relatively inaccessible location in an earth borehole to a'point outside the borehole while concurrently extending the borehole by drilling with means including a hollow drill string through which a stream of drilling fluid flows under pressure, apparatus comprising: a drill string extending from such location to such point, valve means in the drill string, interposed in the path of such stream; actuator means to selectively move thevalve means to positions to produce pressure changes of opposite signs, respectively above and below normal pressure in said stream; means for recurrently securing measures of each of two physical quantities and representing two types of desired information, and for 'periodicallycausing said actuator means to move the valve means to one of said positions for producing a series of reference pressure changes in said stream and after each of said reference pressure changes to causing said actuator means to move the valve means to each of such positions for producing a pressure change of each of said opposite signs and each representing a respective one of said two types of information; and means at said point for receiving and translating such pressure changes into sense-perceptible indications of said measures. p

3. In an investigation system adapted for, use in an earth borehole being drilled by means including a hollow drill string having a downwardly flowing stream of drilling fluid flowing therethrough under pressure, apparatus comprising: a drill string; means to supply. drilling fluid under pressure to said drill string; signal element producing means in the drill string selectively actuatable to produce in such drilling fluid stream, pressure change signal elements both of positive and of negative characteristics with respect to normal pressure; means in the drill string to measure each of two items of interest and to; selectively actuate said signal element producing means to produce a reference pressure-change signal element of a selected one of said characteristics and to thereafter produce measuremcnt-representing pressure change signal elements of each of said characteristics, each such measurement-representing signal element representing by its time spacing from the reference signal element a measurement of one of a respective said items of interest; and means outside the drill string in hydraulic communication therewith for receiving said signal elements and for therewith forming sense-perccptible indications of said measurements.

4. In a system adapted for concurrent investigation of two items of interest at a relatively inaccessible location in an earth borehole, and continued drilling of an extension of the borehole by means including a drill string having a drilling fluid stream flowing therethrough under pressure, apparatus comprising: a section of drill string;

aW L a first means in the drill string selectively actuata-ble to produce pressure changes of opposite sign with respect to normal pressure in the drilling fluid stream; regularly operating means in the borehole for measuring the value of each of said two items and for selectively actuating said .first means to successively produce a reference pressure change of a selected sign in the drilling fluid stream and thereafter at respective time intervals proportional to the measured values of said items, produce measurement-representing pressure changes of opposite signs in the drilling -fl-uid stream each representing a measurement of .-a respective one of said'items of interest; and means outside the borehole and in hydraulic communication with the drilling fluid stream for receiving and translating the several pressure changes into sense-perceptible indications of said measurements.

5. .in a system adapted for concurrent investigation of two items of interest at a relatively inaccessible location in an earth borehole, and continued drilling of an extension of the borehole by means including a drill :string having a drilling fluid stream flowing :therethrough under pressure, apparatus comprising: a first means in the drill :string including :a valve interposed in the .drilltin-gv fluid stream and selectively .actuatable :to produce pressure change signal elements therein of opposite sign with respect :to normal pressure therein; regularly operating actuating and measuring means in the borehole for measuring the value of each of said two items and for selectively actuating said valve to successively produce a reference pressure change signal element of a selected sign in the drilling fluid stream and to thereafter at re spective time intervals proportional to respective of the measured values, produce measu-rement represouting pressure change signal elements of such opposite signs in the drilling fluid stream, each representing a measurement of a respective one of said items of interest and means outside the borehole and in hydraulic communication with the drilling fluid stream for receiving and recording the several pressure change signal elements in the form of a graphical record indicative of said measurements.

6. in an investigation system adapted for use in an earth borehole being drilled'by means including a hollow drill string having a downwardly flowing stream of drilling fluid flowing therethrough under pressure, apparatus comprising: a drill string and means to supply a stream of drilling fluid under pressure to the upper end of the drill string; a first means in the drill string selectively 'a-ctuatable to produce pressure changes of either positive or negative character with respect to normal pressure in said stream of drilling fluid; a second means in the drill string including regularly operated means for measuring values or two items of interest at a location within the borehole and for selectively actuating said firstmeans to cause the latter to produce a reference pressure change signal element of positive character and two succeeding pressure change signal elements, one p.osi rive and one negative, at intervals following said reference' pressure change indicative of and mathematically related to measured values of respective items .of interest; and means including pressure transducer means in hydraulic communication with the upper end of said drill string for detecting and translating said pressure change signal elements to sense-perceptible indications of said measured values.

7'. Ina system for communicating information vof two types from a relatively inaccessible location in an earth borehole to a point outside the borehole While concurrently extending the borehole by drilling with means including a hollow drill string through which a stream of drilling fluid flows under pressure, apparatus comprising: a drill string and means for supplying a stream of drilling fluid under pressure to the drill string; means including a valve means interposed in said stream in said drill string and selectively actuatable =t-ozfirst and second positions to create in said stream respective distinctive pressure change signal elements of first and second characteristics different from normal pressure characteristics; regularly operating means in said drill string to cause actuation of said valve means toone of said positions at periodic intervals; means controlled by :said regularly operating means to procure information of one of said types and to cause actuation of said valve means to one of said positions in response to and in a manner representative of said information of one type; other means in said drill string controlled by said regularly operating means to procure information :of {the other of said two types and to cause actuation of said valve means to the second of said positions ,in -.a manner representative of said other type of information; and means at said point in hydraulic communication in said stream for detecting and translating the pressure changes producedin said stream by said valve means, into :a senseperceptible indication representing said types of information.

.8. .In a system for communicating information com cerning physical quantities of two types from a relatively inaccessible location in an earth borehole to .a point outside the borehole, --while concurrently extending :the borehole by drilling with means including a hollow drill string through which :a stream of drilling .fluid flows under pressure, apparatus comprising: a drill string and means to supply va stream of drilling fluid under pressure to the drill string; means in the drill string including :a valve means interposed in said stream and actuatable in first and second directions from a normal position to create in said stream pressure changes of respective first and second characteristics different from normal pressure characteristics, each of which pressure changes constitutes a signal element; first actuator means for actuau ing said valve means in said first direct-ion; second actuator means for actuating said valve means in said second direction; means including regularly operating means in .the .drill string to regularly energize said first actuator means, first and second mensuration means controlled by said regularly operating means for measuring each of said two physical quantities and for each energizing :a respective vone .of said actuator means at a time interval following energization thereof by said regularly operable means proportional .to its respective measurement means .outside the borehole in hydraulic communication with said stream for detecting and translating the pressure changes in said stream; and recorder means for forming a graphical record vof the characteristic and reception time of .each of the pressure changes detected and translated.

9.. In a method of communicating two types of mensuration information from a relatively inaccessible location in an earth borehole to a point outside the borehole, while concurrently extending the borehole by continued drilling, the concurrent steps comprising: providing a downwardly flowing stream of drilling fluid under pres sure as a signal transmission medium; creating in .said stream .at said location .at regular time intervals, pressure changes of :a uniform characteristic and selected from the class of pressure changes including pressure increase and pressure decrease from a normal pressure, to provide a series of signal intervals and references signal elements; creatingin said stream a series of pressure-increase signal elements, substantially one for each reference signal elementand each spaced from its respective reference signal element in time by an interval representing a measurement comprised in a first of said types of information; creating in said stream a series of pressure-decrease signal elements, substantially one for each reference signal element and each spaced from its respective reference signal element in time by an interval representing a measurement comprised in a second of said types of information; detecting and translating at said point the pressure changes created in said stream; and forming a graphical record of the time spacing and characteristics of said pressure changes.

10. In an earth borehole investigation-signaling system adapted to provide at a point outside an earth borehole, measurements of first and second physical quantities at a relatively inaccessible location within the borehole, during extension of the borehole by drilling by means including a hollow drill string through which a stream of drilling fluid flows under pressure, apparatus comprising: a drill string and means to supply a stream of drilling fluid under pressure to the drill string; an electromagnetically actuated valve interposed in said stream in the drill string and operable in first and second directions from a normal position to produce pressure change signal elements of respectively opposite pressure change characteristics in said stream and comprising first and second electromagnets to operate the valve in respective of said directions; means including electric power means acting to recurrently energize said first electromagnet at regular intervals to produce in said stream a series of reference pressure change signal elements of a given one of said characteristics, and first and second measuring means to measure respective of said first and second physical quantities and energize respective of said first and second electromagnets at respective time intervals following each said reference signal element proportional to the respective measurement, to produce in said stream information-representing signal elements of opposite pressure change characteristics; means at said point in hydraulic communication with said stream for detecting and translating the pressure change signal elements created in said stream and producing a graphical record indicating the relative time spacing and characteristic of each of said detected signal elements.

11. In a system adapted for investigation of physical quantities associated with formations of the earth adjacent the interior of an earth borehole and in which the borehole is drilled by means including a tubular drill string through which drilling fluid flows downwardly under pressure, apparatus comprising: a lower end portion of such drill string; actuatable means located in said lower end portion of said drill string and capable, upon selective energization under first and second different conditions, of producing respective pressure changes of positive and negative sign respectively above and below normal pressure in said drilling fluid thereabove; means in said portion of such drill string for measuring values of said first and second of said physical quantities and for first energizing said actuatable means under the first of said different conditions to produce a pressure change of one such sign as a reference pressure change signal element, and to thereafter at respective time intervals following production of such reference signal element representing the measured values, energizing said actuatable means under each of said first and second different conditions to produce respective positive and negative pressure change signal elements to complete creation in said drilling fluid of a signal representing said measured values; and means including means in hydraulic communication with drill string, to receive said signal from the drilling fluid and to translate said signal into senseperceptible indications indicative of said measured values.

12. Apparatus for communicating information of two types from a relatively inaccessible location in an earth borehole, comprising in combination: a section of tubular drill string adapted for use at such location and having a passageway through which drilling fluid may be forced to flow; means in said section of drill string for recurrently making measures of the value of each of two physical quantities; and means in said section of drill string for selectively increasing and decreasing the resistance of said passageway to flow of fluid therethrough above and below a normal flow resistance value, and governed by said first-mentioned means to recurrently change the said resistance of said passageway in at least one such way and after each such recurrent change, change the said resistance of said passageway in each way from said normal value at respective times following said recurrent change representing the corresponding measures of the values of said physical quantities.

13. In a method of communicating measurements of the values of two kinds of physical quantities from a relatively inaccessible location in an earth borehole to the top thereof while concurrently extending the borehole by continued drilling, the steps comprising: flowing a stream of fluid under pressure through at least a portion of said borehole between said location and an exterior point adjacent the top thereof; establishing a time reference; taking a measure adjacent said location of the value of each of said two physical quantities; producing in the said stream of fluid adjacent said location, in response to one of said measures, a pressure increase above the average pressure thereof and at a time interval following said time reference indicative of the measure of said one of said values; and producing in the said stream of fluid adjacent said location, in response to the other of said measures, a pressure decrease below the average pressure thereof and at a time interval following said time reference indicative of the measure of said other of said values, whereby said pressure increases and said pressure decreases are transmitted flirough said stream of fluid to a reception point exterior of said borehole, the times of arrival thereof at said reception point relative to said time reference being indicative of the values of said physical quantities.

14. In a method of communicating measurements of the values of two kinds of physical quantities from a relatively inaccessible location in an earth borehole to the top thereof while concurrently extending the borehole by continued drilling, the steps comprising: flowing a stream of fluid under pressure through at least a portion of said borehole, between said location and a point adjacent the top thereof; taking measures adjacent said location of the value of each of said two physical quantities; producing in said stream of fluid adjacent said location, pressure increases above the average pressure thereof in, response to and having time distributions indicative of the said measures of the values of one of said physical quantities, and producing in the said stream of fluid adjacent said location pressure decreases below the average pressure thereof in response to and having time distributions indicative of the said measures of the values of the other of said physical quantities, whereby said pressure increases and said pressure decreases are transmitted through said stream of fluid to a reception point exterior of said bore hole, the time distribution of arrival thereof at said reception point being indicative of the values of said physical quantities.

References Cited in the file of this patent UNITED STATES PATENTS 2,380,520 Hassler July 31, 1945 

1. IN A SYSTEM FOR COMMUNICATING INFORMATION OF TWO TYPES FROM A RELATIVELY INACCESSIBLE LOCATION IN AN EARTH BOUREHOLE TO A POINT OUTSIDE THE BONEHOLE WHILE CONCURRENTLY EXTENDING THE BOREHOLE BY DRILLING WITH MEANS INCLUDING A HOLLOW DRILL STRING THROUGH WHICH A STREAM OF DRILLING FLUID FLOWS UNDER PRESSURE, APPARATUS COMPRISING: A SECTION OF SUCH DRILL STRING; MEANS IN THE SECTION OF DRILL STRING TO RECURRENTLY MEASURE EACH OF TWO PHYSICAL QUANTITIES AND TO PRODUCE IN SUCH STREAM PRESSURE CHANGE SIGNALS, EACH COMPRISING ONE OF A SERIES OF REGULARLY PRODUCED REFERENCE PRESSURE CHANGE SIGNAL ELEMENTS OF A GIVEN CHARACTER AND TWO INFORMATION-REPRESENTING PRESSURE CHANGE SIGNAL ELEMENTS ONE ABOVE AND THE OTHER BELOW AN AVERAGE PRESSURE VALVE AND EACH REPRESENTING A RESPECTIVE MEASURE OF SAID PHYSICAL QUANTITIES; AND MEANS OUTSIDE THE BOREHOLE FOR RECEIVING AND TRANSLATING SAID SIGNALS. 